Preventive maintenance of variable speed drives is critical in industrial plants where power electronics determine production continuity. GDM works on a wide range of industrial electronics, including variable speed drives, servomotors, spindles and robotics. However, this article focuses specifically on variable speed drives, as they have a significant impact on reliability, energy consumption and unplanned downtime.
Rather than offering a generic overview, the aim is to provide specific technical criteria to help the maintenance department decide when and how to take preventive action on a drive with the support of a specialist repairer such as GDM.
Why frequency converters require specific preventive maintenance.
A frequency converter incorporates sensitive electronics, thermally demanding components, and variable load cycles. Unlike other electrical equipment, it usually degrades silently until a functional failure occurs.
Capacitor ageing, loss of cooling efficiency and internal connection fatigue do not always generate immediate alarms. For this reason, preventive maintenance of drives should be based on a combination of hours of service and criteria of risk and criticality of the process in which the equipment operates.
The roles of the maintenance department and GDM.
The plant’s maintenance department is responsible for the operational control of the drive. When an anomaly is detected or a preventive inspection is scheduled, the equipment is taken out of service and sent to GDM.
GDM does not carry out work in the field or conduct on-site inspections. Its value lies in carrying out preventive and corrective maintenance in the workshop, where in-depth work can be done on the drive and controlled procedures applied to return the equipment to the customer in optimal operating condition for reinstallation.
This is a technical checklist for the preventive maintenance of variable speed drives in the workshop.
In order to be practical, the preventive maintenance of variable speed drives must be structured around specific checks. The following checklist summarises the critical points that GDM covers in the workshop, with the content adapted according to the type of variable speed drive and its application.
Before any intervention, the customer’s provided equipment documentation and history are reviewed. Maintenance then focuses on:
- The condition of the heat sinks and cooling system, paying special attention to the fans and air flow.
- Evaluation of DC bus capacitors, including measurement of ESR and signs of thermal ageing.
- Review of snubbers, drivers, and internal power and control connections.
- Functional electrical verification and parameter backup are performed to ensure reliable reinstallation.
This approach avoids indiscriminate replacements and prioritises actions that have a real impact on the drive’s service life.
Criteria for prioritising preventive maintenance:
The level and frequency of intervention required for drives varies. The criticality of the industrial process must be taken into account when planning preventive maintenance of drives.
Equipment affecting continuous production, personal safety or just-in-time processes requires more thorough preventive maintenance. In such cases, GDM provides the maintenance department with technical support, offering objective criteria to help decide between reconditioning, partial replacement or replacement planning.
Technical documentation and return to the plant.
Clear documentation must be produced for each preventive intervention. The technical report enables the company to track the current status of the drive and plan future actions.
Furthermore, comparing the cost of preventive maintenance with the potential cost of an unplanned shutdown helps to inform data-driven decision-making. This enables the drive to cease being a reactive element and become part of an industrial reliability strategy.
Would you like to arrange preventive maintenance for your frequency converters? Send your equipment to GDM and request specialised technical advice using our contact form. We will help you to restore and extend the service life of your industrial electronics using professional criteria.
